Iceweasel 10 is in the Debian Unstable repository, so you can easily install it by temporarily enabling that repository.

Pin-priority is adjusted by editing the file /etc/apt/preferences as root. But unless there is something wrong, you shouldn't need to do that if you have the relevant repository enabled. Most repositories are by default assigned a relatively high pin-priority of 500 in that file.

APT-pinning is most easily done via Lock Version on the Package menu in Synaptic, although it can also be done by assigning a package a low priority in the above file.

The next file involved is: /etc/apt/preferencesThe 'preferences' file is where the actual pinning takes place. To pin a package, set its Pin-Priority to higher number. Here's an example:

https://help.ubuntu.com/8.04/serverguide/C/apt-get.htmlapt help..It is also likely that whichever package manager you use can enable pinning in some manner, selecting specific repositories or enabling particular software packages to stick at one version (that is pinning)--since the package managers are in general only a front end to apt package management

Just add the repository you want to use into /etc/apt/sources.list file, then

thanks for your encouragementbut I don't understand this all.So I think I have two possibilitiesfirst to wait until Mint starts to bring new updates for LMDE.Second is to download IceWeasel separately and install it overthe existing version.

Hi Brian49,I did what you recommended.Set your code into the sources.lst.Then sudo apt-get update,next sudo apt-get dist-upgrade,all questions with Y/N I answered with 'Y',then I turned my notebook completly (not only restart)off and and then on again.Now I'm running on my old Pentium III notebookwith kernel 3.2.0.1-amd64 and Gnome 3.2.It's running fast and stable without any errors.Thanks a lot for help.